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Feasibility study for a low-level radon reference chamber concluded


Within the scope of the majority of radon measurements in houses or at the workplace, relatively small radon activity concentrations are measured (the arithmetic mean value lies at 50 Bq/m3). These data are used within the scope of epidemiological studies for the determination of the lung cancer risk.

The devices used for the determination of the radon activity concentration are, however, traceably calibrated only in the range above 1000 Bq/m3. For years now already, PTB has been receiving enquiries from at home and abroad regarding a calibration with reference atmospheres in the range of 100 Bq/m3. All domestic and international recommendations for the 222Rn activity concentration in living quarters meanwhile specify threshold values below the smallest value available at PTB. As radon measurement is currently becoming increasingly important in society (e.g. in the fields of health care, energy-saving measures and medical radioprotection), the setting up of a Low Level Radon Reference Chamber (LL-RRC) was tested within the scope of a feasibility study. According to the present results, the unit can be realised with an uncertainty of 5 % (k=2) for this range of activity concentration.